Pictures are as taken out of engine... nothing touched on the spark plug.
Overall the engine runs pretty well.. I was just at the field and put another 3 flights on the engine. The only 2 things I'm trying to understand.. and I fully agree its likely a tuning issue that I'm going through.... is that I don't always get the engine to kill when I flip the cutoff switch ( I have a battery-> electronic cutoff -> ignition setup ) and also occasionally my midrange goes away.. meaning reducing throttle from full throttle to 1/2 throttle results in no change in the engine rpms.... happens maybe 1 or 2 times a flight. I wouldn't be surprised if I'm rich... I'm assuming you mean I'm rich on the low speed needle and not the high speed?
Overall the engine runs great... just a couple weird issues I'm trying to iron out in my own setup.
ORIGINAL: Pete Bergstrom
Matt,
We haven't seen this behavior in any of our testing. I would look into the following:
1. If you remove your on/off ignition switch from the battery/ignition loop (i.e. just plug directly into the battery pack) does this solve the problem? If it does, replace your switch. if not:
2. Pull your spark plug and see if you have an accumulation of carbon on the plug. The carbon might be retaining enough heat that the engine continues to run in a compression mode (ala a glow engine.) Clean any accumulated carbon from the plug and retry to see if this solves the problem. If there is an accumulation of carbon this is a good indicator you are running the engine a bit too rich.
Pete